• ETRI Journal
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• v.26 no.4
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• pp.285-291
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• 2004

We prepared a novel multi-functional dual-layer polymer electrolyte by impregnating the interconnected pores with an ethylene carbonate (EC)/dimethyl carbonate (DMC)/lithium hexafluorophosphate $(LiPF_6)$ solution. The first layer, based on a microporous polyethylene, is incompatible with a liquid electrolyte, and the second layer, based on poly (vinylidenefluoride-co-hexafluoropropylene), is submicroporous and compatible with an electrolyte solution. The maximum ionic conductivity is $7{\times}10^{-3}S/cm$ at ambient temperature. A unit cell using the optimum polymer electrolyte showed a reversible capacity of 198 mAh/g at the 500th cycle, which was about 87% of the initial value.

• Korean Journal of Materials Research
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• v.23 no.12
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• pp.695-701
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• 2013

To understand how reactivity between reinforcing nanoparticles and aqueous solution affects electrodeposited Cu thin films, two types of commercialized cerium oxide (ceria, $CeO_2$) nanoparticles were used with copper sulfate electrolyte to form in-situ nanocomposite films. During this process, we observed variation in colors and pH of the electrolyte depending on the manufacturer. Ceria aqueous solution and nickel sulfate ($NiSO_4$) aqueous solutions were also used for comparison. We checked several parameters which could be key factors contributing to the changes, such as the oxidation number of Cu, chemical impurities of ceria nanoparticles, and so on. Oxidation number was checked by salt formation by chemical reaction between $CuSO_4$ solution and sodium hydroxide (NaOH) solution. We observed that the color changed when $H_2SO_4$ was added to the $CuSO_4$ solution. The same effect was obtained when $H_2SO_4$ was mixed with ceria solution; the color of ceria solution changed from white to yellow. However, the color of $NiSO_4$ solution did not show any significant changes. We did observe slight changes in the pH of the solutions in this study. We did not obtain firm evidence to explain the changes observed in this study, but changes in the color of the electrolyte might be caused by interaction of Cu ion and the by-product of ceria. The mechanical properties of the films were examined by nanoindentation, and reaction between ceria and electrolyte presumably affect the mechanical properties of electrodeposited copper films. We also examined their crystal structures and optical properties by X-ray diffraction (XRD) and UV-Vis spectroscopy.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.12
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• pp.1002-1006
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• 2010

In this study, magnesium (Mg), zinc (Zn) and aluminium (Al) as anode electrode and the solution of NaCl dissolved with 2~20 wt% as electrolytes were used for the metal-air cell. The open circuit voltage, short circuit current and I-V characteristics upon different kinds of anode electrode and electrolyte concentration were investigated. The open circuit voltage, initially about 1.45 V, rises to 1.6 V during the first 10 minutes indicating the necessity of an induction time to activate the catalyst on the air cathode. The short circuit current increases with an increased concentration of NaCl, causes an increase in the conductivity of the electrolyte solution, but the open circuit voltage did not under undergo influence of electrolyte. From NaCl 20 wt% electrolyte, the maximum output power of the magnesium electrode materials was measured with 177mW. It is found that the power characteristics of metal-air cell could be improved by using magnesium electrode materials in the NaCl electrolyte.

• Journal of the Korean Vacuum Society
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• v.8 no.4B
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• pp.524-529
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• 1999

We deposited diamond phase carbon thin films on Si substrate by the electrolysis of methanol solution. A little amount of ammonia solution was added to increase the current density of the electrolyte. We analyzed films by XRD and SEM. The chemical change of electrolyte during the electrolysis process was characterized by FTIR. We obtained better quality diamond phase carbon films at a lower applying boltage(300V) and temperature ($40^{\circ}C$) by adding ammonia solution to methanol electrolyte. Diamond (111), (220), (311) peaks were shown distinctively in XRD graph. Addition of ammonia solution resulted in lowering the applying bias voltage to 300V and the substrate temperature to $40^{\circ}C$ still maintaining a high current density at 80mA/$\textrm{cm}^2$, which prohibited a great loss of solution from vaporization. Possible change of chemical reaction due to the addition of ammonia solution was also discussed.

• Journal of Convergence for Information Technology
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• v.11 no.2
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• pp.117-123
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• 2021

The effects of electrolyte concentration on the electrochemical properties of Fe4[Fe(CN6)]3(FeHCF) as a novel active material for the electrode of aqueous zinc-ion batteries was investigated. The electrochemical reactions and structural stability of the FeHCF electrode were significantly affected by the electrolyte concentration. In the electrolyte solutions of 1.0-7.0 mol dm-3, the charge-discharge capacities increased with increasing electrolyte concentration, however gradually decreased as the cycle progressed. On the other hand, in the 9.0 mol dm-3 electrolyte solution, the initial capacity was relatively small, however showed good cyclability. Additionally, the FeHCF electrode after five cycles in the former electrolyte solutions, had a change in crystal structure, whereas there was no change in the latter electrolyte solution. This suggests that the performance of the FeHCF electrode is greatly influenced by the hydration structure of zinc ions present in electrolyte solutions.

• Journal of Technologic Dentistry
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• v.38 no.2
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• pp.79-84
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• 2016

Purpose: The aim of this study was to make nanomesh on the surface of titanium by potentiostatic technique which was done at the suitable potential level. Methods: In order to find the suitable potential level, use a $25^{\circ}C$ NaCl, NaOH and NH4F solution of 1 M and 5 M as supporting electrolyte, working electrode(positive potential) was contact to the titanium specimen and counter electrode(negative potential) was contact to the Pt substrate. At the transpassive potential which was observed by potentiostatic technique, potentiostatic technique was done for 2hours. Results: As a result, 1 M NaOH solution was suitable as a supporting electrolyte, potentiostatic technique used a $25^{\circ}C$ NaOH solution of 1 M for 2hours, nanomesh was formed. Conclusion: The potentiostatic technique was used $25^{\circ}C$ NaOH solution of 1 M and 5 M as supporting electrolyte for 2hours. Nanomesh was built more uniform and fine in 1 M NaOH solution than 5 M NaOH solution.

• Corrosion Science and Technology
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• v.10 no.2
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• pp.71-75
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• 2011

Corrosion properties of Al-0.3Ga-0.3Sn, Al-0.3Mn-0.3Ga, and Al-0.3Mn-0.3Sn alloys were examined to develop an anode material for Al-air battery with alkaline aqueous or ethanol electrolyte. The results of potentiodynamic polarization tests showed that the electrode potential of the Al alloys were lower than the pure Al, implying the cell voltage can be increased by using one of these alloys for an anode in 4 M KOH aqueous solution. The corrosion rate appeared to be increased by alloying Ga but to be reduced by Sn and Mn in the aqueous solution. The ethanol solution is expected to improve the cell performance in that the electrode potential and the corrosion rate of Al were lower in ethanol solution than in aqueous solution. However the Al-(Ga, Sn, Mn) alloys are not favorable in ethanol solution because of the high potential and corrosion rate.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.64 no.4
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• pp.303-307
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• 2015

The effects of additive such as $H_2O_2$ in KOH electrolyte solution for the Aluminum/Air fuel cell were investigated with regard to electric power characteristics. The power generated by a Al/Air fuel cell was controlled by the KOH electrolyte solution and $H_2O_2$ depolarizer. Higher cell power was achieved when higher KOH electrolyte concentration and higher $H_2O_2$ depolarizer amount. The maximum power was increased by the increase amount $H_2O_2$ depolarizer, it was found that $H_2O_2$ depolarizer inhibits the generation of hydrogen and the polarization effect was reduced as a result. Internal resistance analysis was employed to elucidate the maximum power variation. Higher internal resistance created internal potential differences that drive current dissipating energy. In order to improve the output characteristics of the Al/Air fuel cell, it is thought to be desirable to increase the KOH electrolyte concentration and increase the $H_2O_2$ addition amounts.

• Korean Journal of Materials Research
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• v.27 no.12
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• pp.672-678
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• 2017

In the production of zirconium cladding tube, a pickling acid solution is used to remove surface contaminants, which generates tons of pickling acid waste. The waste pickling solution is a valuable resource of Hf-free Zr. Many studies have investigated separating the Hf-free Zr source from the waste pickling acid. The results showed that $Ba_2ZrF_8$ precipitates prepared from the waste pickling acid were useful as an electrolyte for the electrorefining of Zr in molten salt. In the present work, electrorefining was performed in a $Ba_2ZrF_8-LiF$ binary electrolyte to recover Zr from a Hf-free CuZr ingot anode prepared by electroreduction. Before electrorefining, two pretreatments are performed. First, electrolyte melting was carried out to determine the eutectic temperature, and second, the electrolyte was treated to eliminate impurities, mainly hydride. After electrorefining, the cathode deposits were analyzed by $O_2$ gas analyzer and SEM-EDX to explore the possibility of recovering nuclear-grade Zr metal. Moreover, the anode was analyzed by SEM-EDX to determine the Zr dissolution depth.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.9
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• pp.1626-1631
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• 2010

The characteristics of electric current for the voltaic cell are important for electric power applications. In this paper, an electrical equivalent model consist of three resisters and a capacitance for the Cu/NaCl solution/Zn electrochemical cell is proposed. The capacitance which exists in the Zn electrode/electrolytic interface increased according to Zn electrode area, but cannot affect almost in electric current. Complex impedance plot was used to analysis the interface effect for Zn/electrolyte. This result shows that the interface is similar with the electric transmission line. The short current measurements were conducted to investigate the effects of hydrogen peroxide, the watery sulfuric acid and NaCl aqueous solution. As the hydrogen peroxide increased, the electric current increased because the hydrogen gas being converted with the water. Also electric current increased significantly with increase of the hydrogen ion with the watery sulfuric acid and increased with increase of $Na^+$ ion and $Cl^-$ion in the NaCl electrolyte.